Detrended Price Oscillator

DetrendOsc.efs  
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File Name: DetrendOsc.efs

Description:
Detrended Price Oscillator

Formula Parameters:

• Length : 14
• Source of Price : Close

Notes:
The Detrend Price Osc indicator is similar to a moving average, in that it filters out trends in prices to more easily identify cycles. The indicator is an attempt to define cycles in a trend by drawing a moving average as a horizontal straight line and placing prices along the line according to their relation to a
moving average. It provides a means of identifying underlying cycles not apparent when the moving average is viewed within a price chart. Cycles of a longer duration than the Length (number of bars used to calculate the Detrend Price Osc) are effectively filtered or removed by the oscillator.

Download File:
DetrendOsc.efs


EFS Code:

/*********************************
Provided By:  
    eSignal (Copyright c eSignal), a division of Interactive Data 
    Corporation. 2009. All rights reserved. This sample eSignal 
    Formula Script (EFS) is for educational purposes only and may be 
    modified and saved under a new file name.  eSignal is not responsible
    for the functionality once modified.  eSignal reserves the right 
    to modify and overwrite this EFS file with each new release.

Description:        
    Detrended Price Oscillator
    
Version:            1.0  04/13/2009

Formula Parameters:                     Default:
    Length                              14
    Source of Price                     Close

Notes:
    The Detrend Price Osc indicator is similar to a moving average, 
    in that it filters out trends in prices to more easily identify 
    cycles. The indicator is an attempt to define cycles in a trend 
    by drawing a moving average as a horizontal straight line and 
    placing prices along the line according to their relation to a 
    moving average. It provides a means of identifying underlying 
    cycles not apparent when the moving average is viewed within a 
    price chart. Cycles of a longer duration than the Length (number 
    of bars used to calculate the Detrend Price Osc) are effectively 
    filtered or removed by the oscillator.
**********************************/
var fpArray = new Array();
var bInit = false;

function preMain() {
    setStudyTitle("Detrended Price Oscillator"); 
    setCursorLabelName("Detrend Osc",0);
    setDefaultBarFgColor(Color.red,0);
    addBand(0, PS_SOLID, 1, Color.blue, 1);    
    var x=0;
    fpArray[x] = new FunctionParameter("nLength", FunctionParameter.NUMBER);
    with(fpArray[x++]) {
        setName("Length");
        setLowerLimit(1);
        setDefault(14);
    }
    fpArray[x] = new FunctionParameter("sPrice", FunctionParameter.STRING);
	with(fpArray[x++]){
        setName("Source of Price");
        addOption("open"); 
        addOption("high");
        addOption("low");
        addOption("close");
        addOption("hl2");
        addOption("hlc3");
        addOption("ohlc4"); 
        setDefault("close"); 
    }    
}

var xDPO = null;

function main(sPrice, nLength) {
var nBarState = getBarState();
var nResult = 0;
    if (nBarState == BARSTATE_ALLBARS) {
        if (sPrice == null) sPrice = "close";        
        if (nLength == null) nLength = 14;
    }
    if (bInit == false) {
        xDPO = efsInternal("Calc_DPO", nLength, sPrice);
        bInit = true;
    }
    nResult = xDPO.getValue(0);
    return nResult;
}

var xSMA = null;
var xSource = null;
var bSecondInit = false;

function Calc_DPO(nLength, sPrice) {
var nRes = 0
    if (getCurrentBarCount() <= nLength) return;
    if (bSecondInit == false) {
        xSource = eval(sPrice)();
        xSMA = sma(nLength, xSource);
        bSecondInit = true;
    }
    nRes = xSource.getValue(0) - xSMA.getValue(0);
    return nRes;
}